Effluent is wastewater from sewers or industrial outfalls that either flows directly into surface waters or is discharged indirectly after being treated at a facility.[1] The term “effluent” has slightly different meanings and may contain various pollutants depending on the source.[2][3] Industrial discharge of effluent is regulated under the Clean Water Act which is enforced by the Environmental Protection Agency in the United States.[1] Pretreating effluent efficiently is challenging, but improved technology allows for enhanced removal of specific materials, increased re-use of water, and energy production from waste.[2][4][5][6]
Definition
Effluent is defined by the United States Environmental Protection Agency as "wastewater - treated or untreated - that flows out of a treatment plant, sewer, or industrial outfall. Generally refers to wastes discharged into surface waters".[7] The Compact Oxford English Dictionary defines effluent as "liquid waste or sewage discharged into a river or the sea".[8]
Description
Effluent in the artificial sense is in general considered to be water pollution, such as the outflow from a sewage treatment facility or the industrial wastewater discharge from industrial facilities. An effluent sump pump, for instance, pumps waste from toilets installed below a main sewage line. In the context of waste water treatment plants, effluent that has been treated is sometimes called secondary effluent, or treated effluent. This cleaner effluent is then used to feed the bacteria in biofilters.[9]
In the context of a thermal power station and other industrial facilities, the output of the cooling system may be referred to as the effluent cooling water, which is noticeably warmer than the environment and is called thermal pollution.[10]: 375 Effluent, in engineering, is the stream exiting a chemical reactor.[11]
Effluent may carry pollutants such as fats/oils/greases, chemicals, detergents, heavy metal rinses, solids, and food waste.[2] Possible sources include municipalities, food processing, textile industry, leather-making, biodiesel production, the medical industry, and aquaculture.[3]
Pollution control regulation
In the United States, the Clean Water Act requires all direct effluent discharges to surface waters to be regulated with permits under the National Pollutant Discharge Elimination System (NPDES) and all indirect discharges to treatment facilities to abide by the Pretreatment Program.[12][1] The permits require discharging facilities to limit or treat effluent to the levels that result from using the most effective treatment technologies possible at a practical cost to mitigate the effects of discharges on the receiving waters.[1] There are established standards for fifty-nine different industrial sources of effluent.[13] It is mandatory for the Environmental Protection Agency to update the standards every year, and research regarding several sources of effluent are ongoing.[1] Incompliance with these standards is punishable by law.[14] Each year, these regulations stop billions of pounds of contaminants from being released into bodies of water.[15]
Pretreatment
When pretreating effluent, it is difficult to reduce expenses, increase productivity, adhere to stringent standards, and prevent discharge of byproducts.[2] Furthermore, depletion of clean, fresh, accessible water is a global issue, but evolving technology can help prevent this because improving treatment methods allows for re-use of water.[5] Additionally, waste-to-energy technology transforms organic matter into usable electricity, heat, or fuel.[6] Treatments also exist to remove certain elements, compounds, salts, and minerals from effluent.[4]
See also
- Effluent guidelines (U.S. wastewater regulations)
- Effluent limitation
- Wastewater
References
- ^ a b c d e US EPA, OW (2014-02-28). "Learn about Effluent Guidelines". www.epa.gov. Retrieved 2022-11-30.
- ^ a b c d "StackPath". www.wwdmag.com. Retrieved 2022-11-30.
- ^ a b Barik, Debabrata (2019), "Introduction to Energy From Toxic Organic Waste For Heat and Power Generation", Energy from Toxic Organic Waste for Heat and Power Generation, Elsevier, pp. 1–6, retrieved 2022-11-30
- ^ a b Brandt, Malcolm J.; Johnson, K. Michael; Elphinston, Andrew J.; Ratnayaka, Don D. (2017-01-01), Brandt, Malcolm J.; Johnson, K. Michael; Elphinston, Andrew J.; Ratnayaka, Don D. (eds.), "Chapter 10 - Specialized and Advanced Water Treatment Processes", Twort's Water Supply (Seventh Edition), Boston: Butterworth-Heinemann, pp. 407–473, doi:10.1016/b978-0-08-100025-0.00010-7, ISBN 978-0-08-100025-0, retrieved 2022-11-30
- ^ a b Jegatheesan, V.; Shu, L.; Visvanathan, C. (2011), "Aquaculture Effluent: Impacts and Remedies for Protecting the Environment and Human Health", Encyclopedia of Environmental Health, Elsevier, pp. 123–135, retrieved 2022-11-30
- ^ a b (Firm), ProQuest (2018). ENERGY FROM TOXIC ORGANIC WASTE FOR HEAT AND POWER GENERATION. WOODHEAD. ISBN 978-0-08-102529-1. OCLC 1096233045.
- ^ "Terms of Environment". Washington, D.C.: United States Environmental Protection Agency (EPA). February 1993. p. 10. EPA 175=B=93-001.
- ^ "AskOxford: effluent". Ask Oxford.com. Oxford University Press. 2010. Retrieved 2010-06-09.[dead link]
- ^ Wastewater engineering: Treatment and reuse (4th ed.). Boston: McGraw-Hill. 2003. ISBN 0-07-041878-0. OCLC 48053912.
{{cite book}}: Unknown parameter|authors=ignored (help) - ^ Laws, Edward A. (2017). Aquatic Pollution: An Introductory Text (4th ed.). Hoboken, NJ: John Wiley & Sons. ISBN 9781119304500.
- ^ Fogler, H. Scott (2006). Elements of Chemical Reaction Engineering. Hoboken, NJ: Prentice Hall. p. 43. ISBN 9780131278394.
- ^ "NPDES Permit Limits". National Pollutant Discharge Elimination System. EPA. 2021-10-11.
- ^ US EPA, OW (2015-07-16). "Industrial Effluent Guidelines". www.epa.gov. Retrieved 2022-11-30.
- ^ US EPA, OW (2014-02-28). "Effluent Guidelines Implementation & Compliance". www.epa.gov. Retrieved 2022-11-30.
- ^ US EPA, OW (2014-02-27). "Effluent Guidelines Plan". www.epa.gov. Retrieved 2022-11-30.